Heretofore utilized asphalt pavers have feed conveyors and spreader augers which are mechanically coupled together and driven by single drive motors. They include strike-off gates which are vertically movable and are raised or lowered for the purpose of varying the depth of the asphalt material which is deposited on the feed conveyors to vary the quantity of material which is delivered from the hopper to the region forwardly of the screed.
These heretofore utilized pavers also had first and second separate systems that where substantially identical with substantially identical controlling apparatus. Therefore two "streams" of asphalt were laid down simultaneously and the screed and other apparatus were adapted to blend the two streams together to form a resultant uniform asphalt pathway. The word "asphalt" as used herein means paving material whether it actually contains asphalt (bitumen) or not.
It is therefore desirable to provide controlling apparatus that is highly automated since there are so many adjustments that an operator must make to produce a uniform asphalt pathway. It is also desirable to reduce the number of elements on the machine to as few as possible to prevent waste of materials and labor. This is particularly true of elements which can be replaced by off the shelf elements which are well known and whose reliability has been proven.
An example of heretofore known pavers is described in U.S. Pat. No. 4,012,160 "Paving Machine With Enclosed Material Compartment" which issued on Mar. 15, 1977 to Jimmy L. Parker. This paver has first and second systems for laying down two asphalt streams and each system has a conveyor, a conveyor sensor and an auger and an auger sensor.
In our present invention, each system has only a single sensor. The single sensor is associated with the auger and the conveyor speed is controlled proportionally to the auger speed and said conveyor has no conveyor controlling sensor.
The present invention is also provided with differing separate controlling modules which permit a purchaser to select only those automatic controls which he deems necessary for the types of jobs he generally encounters.
The present invention is directed to overcome one or more of the problems experience in the operation of asphalt pavers.